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<a href="intro.html"><h2>SQLite C Interface</h2></a><h2>Convenience Routines For Running Queries</h2><blockquote><pre>int sqlite3_get_table(
  sqlite3 *db,          /* An open database */
  const char *zSql,     /* SQL to be evaluated */
  char ***pazResult,    /* Results of the query */
  int *pnRow,           /* Number of result rows written here */
  int *pnColumn,        /* Number of result columns written here */
  char **pzErrmsg       /* Error msg written here */
);
void sqlite3_free_table(char **result);
</pre></blockquote><p>
This is a legacy interface that is preserved for backwards compatibility.
Use of this interface is not recommended.</p>

<p>Definition: A <b>result table</b> is memory data structure created by the
<a href="../c3ref/free_table.html">sqlite3_get_table()</a> interface.  A result table records the
complete query results from one or more queries.</p>

<p>The table conceptually has a number of rows and columns.  But
these numbers are not part of the result table itself.  These
numbers are obtained separately.  Let N be the number of rows
and M be the number of columns.</p>

<p>A result table is an array of pointers to zero-terminated UTF-8 strings.
There are (N+1)*M elements in the array.  The first M pointers point
to zero-terminated strings that  contain the names of the columns.
The remaining entries all point to query results.  NULL values result
in NULL pointers.  All other values are in their UTF-8 zero-terminated
string representation as returned by <a href="../c3ref/column_blob.html">sqlite3_column_text()</a>.</p>

<p>A result table might consist of one or more memory allocations.
It is not safe to pass a result table directly to <a href="../c3ref/free.html">sqlite3_free()</a>.
A result table should be deallocated using <a href="../c3ref/free_table.html">sqlite3_free_table()</a>.</p>

<p>As an example of the result table format, suppose a query result
is as follows:</p>

<p><blockquote><pre>
Name        | Age
-----------------------
Alice       | 43
Bob         | 28
Cindy       | 21
</pre></blockquote></p>

<p>There are two column (M==2) and three rows (N==3).  Thus the
result table has 8 entries.  Suppose the result table is stored
in an array names azResult.  Then azResult holds this content:</p>

<p><blockquote><pre>
azResult&#91;0] = "Name";
azResult&#91;1] = "Age";
azResult&#91;2] = "Alice";
azResult&#91;3] = "43";
azResult&#91;4] = "Bob";
azResult&#91;5] = "28";
azResult&#91;6] = "Cindy";
azResult&#91;7] = "21";
</pre></blockquote></p>

<p>The sqlite3_get_table() function evaluates one or more
semicolon-separated SQL statements in the zero-terminated UTF-8
string of its 2nd parameter and returns a result table to the
pointer given in its 3rd parameter.</p>

<p>After the application has finished with the result from sqlite3_get_table(),
it must pass the result table pointer to sqlite3_free_table() in order to
release the memory that was malloced.  Because of the way the
<a href="../c3ref/free.html">sqlite3_malloc()</a> happens within sqlite3_get_table(), the calling
function must not try to call <a href="../c3ref/free.html">sqlite3_free()</a> directly.  Only
<a href="../c3ref/free_table.html">sqlite3_free_table()</a> is able to release the memory properly and safely.</p>

<p>The sqlite3_get_table() interface is implemented as a wrapper around
<a href="../c3ref/exec.html">sqlite3_exec()</a>.  The sqlite3_get_table() routine does not have access
to any internal data structures of SQLite.  It uses only the public
interface defined here.  As a consequence, errors that occur in the
wrapper layer outside of the internal <a href="../c3ref/exec.html">sqlite3_exec()</a> call are not
reflected in subsequent calls to <a href="../c3ref/errcode.html">sqlite3_errcode()</a> or
<a href="../c3ref/errcode.html">sqlite3_errmsg()</a>.
</p><p>See also lists of
  <a href="objlist.html">Objects</a>,
  <a href="constlist.html">Constants</a>, and
  <a href="funclist.html">Functions</a>.</p>
